This invention is directed towards a process of treating hazardous solid-waste materials to decrease the flammability and reduce the burn rate of the materials.
Certain types of solid hazardous waste materials must meet stringent criteria before they will be accepted for disposal by an approved waste disposal company. One such test, which conforms to Method 1030 of the United States Environmental Protection Agency, and which is incorporated herein by reference, sets forth evaluation methods for determining the ignitability of solid waste including pastes, granular materials, and powdery substances. The testing protocols provide for obtaining strips or material trains of the hazardous material and exposing them to a combustion source. Materials that propagate burning along a 200 mm strip or more within a specified time period are then subject to additional evaluation under a burning rate test as set forth in section 7.2 of EPA Method 1030. Materials which exceed an established burn rate are unsuitable for acceptance. Consequently, the entire shipment of hazardous waste from which the samples is taken are rejected.
If the waste is rejected, there is additional cost in the handling and transport of the waste to the waste originator or to another facility. Alternate facilities typically charge a higher disposal fee based upon the enhanced flammability of the material. Accordingly, there is a need for a process that may be used to treat hazardous waste so as to render the waste material less flammable.
It is one aspect of the present invention to provide a dry chemical mixture which may be intermixed with hazardous materials prior to delivery of the hazardous materials for evaluation and disposal. The mixture of dry chemicals act as a fire retardant and lowers the flammability of the materials as evidenced by improved ability to pass a burn progression test.
The process not only facilitates acceptance of the hazardous waste by a waste disposal company, but brings about attendant improvements in the storage, handling, and transport of the treated hazardous material.
Further, the treatment process lends itself to use by the intended waste receiving recipient such that it is possible to now treat a material waste having too high of a flammability property at the waste facility location. Following treatment, subsequent evaluations will establish that the waste may now be accepted by the facility, thereby saving the expense and trouble of returning the waste material to the originator.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description.
Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in, or are obvious from, the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the application. In addition, it should be understood that aspects of the various embodiments may be interchanged, both in whole or in part. Therefore, the spirit and scope of the invention should not be limited solely to the description of the preferred versions contained therein.
As used herein, the term xe2x80x9chazardous materialsxe2x80x9d includes (but is not limited to) combustible solids and flammable solids as defined by the U.S. Department of Transportation as set forth in 49 CRF 173.124 (subpart D) which is incorporated herein by reference.
In accordance with this invention, it has been found that selected dry chemicals may be used to treat hazardous materials. Preferably, the chemical mixture is added to the hazardous materials prior to being loaded for transport to a disposal facility. The chemical mixtures are found to serve as a fire retardant which reduces the burn rate of the hazardous materials when subjected to standard burn progression tests.
As a result, the chemical mixture and application process allows more diverse types of waste to be accepted by a waste disposal facility. Further, by reducing the flammability of the hazardous waste, the storage, shipment, and/or disposal of the waste material is made safer.
In addition, the present invention also offers safer storage of organic contaminated waste materials such as contaminated debris which may include rags, filters, rubber, cotton, nylon, paper, wood, and paint debris. The treatment process provides for a safer storage, disposal, and transportation of combustible hazardous materials.
The efficiency of the treatment process has been demonstrated on several examples upon material waste, such as solvent-containing rags, which had initially failed a burn rate test. Upon application of the chemical mixture as set forth below, the same shipment of hazardous materials would pass the burn rate test and thereafter be acceptable for receipt by the waste disposal facility.
A variety of dry chemicals have been found useful with respect to the present invention. While the use of an individual dry chemical retardant selected from the list below may be operative, it is preferred that mixtures of two or more of the dry chemicals be used to treat the hazardous material.
Dry chemical admixtures found useful in the present invention include: monoammonium phosphate, ammonium sulfate, magnesium aluminum silicate, methyl hydrogen siloxane, barium sulfate, sodium bicarbonate, and potassium bicarbonate. It has been found that mixtures of three or more of these dry chemicals provides a useful admixture for treating hazardous waste. Additional dry chemicals useful for this invention would also include fire retardants and solid extinguishing agents commonly used in pressurized fire extinguishers.
In accordance with this invention, it has been found that solid material contaminated with certain hazardous and flammable materials may be effectively treated using the retardants and process set forth herein. The retardant admixture is found to be effective in treating materials contaminated with acetone, benzene, butane, butylamine, cyclohexane, ethyl benzene, ethyl acrylate, ethanol, isobutenyl ketone, methyl ketone, methyl methacrylate, methanol, methyl acrylate, naphthalene, O-dichlorobenzene, P-dichlorobenzene, phenols, toluene, trichloroethylene, vinyl toluene, xylene, tetrachloroethane, and, lacquer dust. However, the above list is not believed limiting in that other flammable hazardous constituents may be treated by the present protocols.
The following examples set forth useful protocols and procedures for applying the dry chemical admixture to hazardous waste material so as to render the waste material less flammable. It is understood and appreciated that the following examples establish the usefulness and utility of the present invention though variations and relative concentrations of admixtures, types of various admixtures, the coating and/or treatment protocol, may be all be varied depending upon available resources and the characteristic of the hazardous material to be treated.